The invention relates to an electric motor having a fastening flange and a bearing support part made of a plastic material or a soft metal The motor stator is fastened on an outer diameter of the bearing part.
As a rule, the stators of electric motors of this type are glued on a bearing support part Before the hardening of the adhesive agent of the glue, the stator must be aligned, and it must remain in this position until the hardening is completed. The apportioning of the adhesive agent must take place relatively precisely since, due to the small play between the inside diameter of the stator iron and the outer jacket of the bearing support part, only a small amount of this adhesive agent is required It is an important disadvantage of the adhesive agent that the adhesive layer when, for example the bearing support part is pushed on, is pressed away so that no apportioned amount of adhesive agent remains.
The invention is based on the object of eliminating the disadvantages which arise as a result of the gluing and at the same time reducing the costs for the manufacturing of such electric motors. This is accomplished by means of a very simple mounting.
According to the invention, this object is achieved for an electric motor of the initially mentioned type by arranging a metal toothed disk at the end of the stator iron on the side away from the flange Said toothed disk has radially inwardly extending projections which are in external contact with the bearing support part and hold the stator.
By means of a simple axial pressing-on step, the construction of the inventive stator results in the simultaneous fastening and alignment of the stator at the bearing support part.
The fastening device provided in the invention is a simple toothed disk made of strip steel The equidistantly arranged teeth of the toothed disk are made of thin spring steel or strip steel or hard copper, which is thin, elastic and hard, and which are bent away as a result of a residual spring action to hook themselves in the plastic material of the bearing support part when the stator is pressed on the bearing support part. Because of the selected plate thickness of, for example, approximately 0.2 mm, the teeth do not have to be bent forward and then mounted.
At least one tongue, which projects beyond the outer edge of the toothed disk, fixes this toothed disk in a position which is appropriate for mounting Because of the winding spindle, the teeth should always have the same position.
A groove, which extends in axial direction in the inside bore of the stator iron, acts in conjunction with an axial cam, extending axially on the outer jacket of the bearing support part, to prevent any twisting.
For the radial alignment and improved centering, at least three ribs are injection-molded to the outer jacket of the bearing support part, are approximately uniformly distributed over the circumference, and extend in parallel to the axis of the inside bore of the bearing support part.
The toothed disk is inserted between the stator iron and the end plate of the winding and is held by the winding of the stator and thus also by the end plates of the winding. At the same time, the disk is insulated in the direction of the winding wire.
An axially short smaller diameter of the outer jacket is provided at the end of the bearing support part on the side away from the flange to facilitate the mounting and provide a space for the raising of the teeth.
Other details and advantageous further developments of the invention are found in the following description of the embodiments shown in the drawings.